The first riddle I ever heard, one familiar to almost every Jewish child,
was propounded to me by my father:
"What is it that hangs on the wall, is green, wet -- and whistles?"
I knit my brow and thought and thought, and in final perplexity gave up.
"A herring," said my father.
"A herring," I echoed. "A herring doesn't hang on the wall!"
"So hang it there."
"But a herring isn't green!" I protested.
"Paint it."
"But a herring isn't wet."
"If it's just painted it's still wet."
"But -- " I sputtered, summoning all my outrage,
"a herring doesn't whistle!!"
"Right, " smiled my father. "I just put that in to make it hard."
-- Leo Rosten, "The Joys of Yiddish"